Permanent JST connection on PogoPlug mobile

I ruined a board trying to connect a JST connector for permanent serial console access, and I'm hoping to avoid ruining my new board. I see that 3 of the pads are holes and I can easily remove the solder from the holes. Piece of cake.

But the 4th pad (ground) doesn't appear to be a hole at all. No matter how hard I tried (and I obviously tried too hard) I can't get through it. I tried trimming the pin on the connector, so that I'd have 3 pins going all the way through and one just sitting on the pad, with hopefully enough contact to serve as a proper ground.

When I connected the serial cable and powered up, I let the smoke out of something (UART maybe?). I'm guessing it was all my poking and prodding. $7 down the drain -- on to the next board!

How does one properly solder a JST connector in this scenario? I've seen bodhi mention in a few threads that he has connected JSTs to some of his v4 boards, so it must be possible with the proper technique.

I know I can simply solder wires to the pads I need, but I'm looking for something cleaner and more finished, I guess. If I'm trying to do something that's simply beyond my capabilities, then I'll defer to direct wire soldering.

Finally, a confession -- I'm much more adept at software than I am at hardware mods. I have sufficient tools to do the job, just need a little guidance from the more experienced hardware hackers.

Ah, yes -- a good EE is a very valuable friend. Wish I had one that lived a bit closer! Can you tell on your board how they got ground attached?

I though of soldering a wire (my EE buddies would call it snot wire) to the trimmed pin, then looping that over to the bottom side of the board and soldering the other end to the pad on the underside. Not sure if that's a good solution, as I haven't dared to try anything on my pristine board yet.

> Ah, yes -- a good EE is a very valuable friend. Wi
> sh I had one that lived a bit closer! Can you tell
> on your board how they got ground attached?
>

I recalled he desoldered the buttons, and then put in the header, and solder them in. A professional job that looks exactly as factory. That's it. And all I needed to do was identify the correct TX, RX, GND pins and connect them to the serial converter module.

GeekSmith Wrote:
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> @bodhi -- If you have a unit open and accessible,
> can you see if the the ground pin on the socket go
> es all the way through the board?

I too will be out of action for a while. But if you hold on a while I'm sure one of us can try or look. I lack precision soldering equipment (this will change) and more importantly a big, fat magnifying glass on an arm, but one by one the parts are tricking in and shouldn't be too long and hopefully I can try stuff like that.

To that end, I'm thinking of a mid-future Wiki page itemizing the kind of parts that are good to have on hand to cover most stuff. Because these parts are usually cheap and may as well get the 10-30 day delivery out of the way beforehand.

Success! Even with the soldering skills of a software engineer, I was able to attach the JST connector and use it without letting the smoke out. I removed the solder from the 3 holes that go through the board. I also removed as much solder as I could from the pad for ground.

I then clipped the pin on the connector that goes to ground, and used solder paste on the cut pin and the ground pad. I was able to get enough heat from the bottom pad and the top of the pin to make a good electrical connection. I soldered the other 3 pins from the bottom side and the connector is working great.

I have another board to work on, and now that I know how to do it I'll take some pictures to share when I modify that board. Thanks for the tips! Solder paste was the key.

GeekSmith Wrote:
-------------------------------------------------------
> Success! Even with the soldering skills of a softw
> are engineer, I was able to attach the JST connect
> or and use it without letting the smoke out. I rem
> oved the solder from the 3 holes that go through t
> he board. I also removed as much solder as I could
> from the pad for ground.
>
> I then clipped the pin on the connector that goes
> to ground, and used solder paste on the cut pin an
> d the ground pad. I was able to get enough heat fr
> om the bottom pad and the top of the pin to make a
> good electrical connection. I soldered the other 3
> pins from the bottom side and the connector is wor
> king great.
>
> I have another board to work on, and now that I kn
> ow how to do it I'll take some pictures to share w
> hen I modify that board. Thanks for the tips! Sold
> er paste was the key.

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